al·​kyl | \ ˈal-kəl How to pronounce alkyl (audio) \

Definition of alkyl

 (Entry 1 of 2)

: having a monovalent organic group and especially one CnH2n+1 (such as methyl) derived from an alkane (such as methane)



Definition of alkyl (Entry 2 of 2)

: a compound of one or more alkyl groups with a metal mercury alkyls

Examples of alkyl in a Sentence

Recent Examples on the Web: Adjective The alkyl side chain is the driving force behind a cannabinoid's effects on humans. Kristen Rogers, CNN, "Scientists discovered a weed compound that may be 30 times more powerful than THC," 3 Feb. 2020 Recent Examples on the Web: Noun The second concern, Radić says, is that A-232’s alkyl amine group could enable it to target other enzymes in addition to AChE—and that raises the specter of severe symptoms arising months or years after exposure. Richard Stone, Science | AAAS, "U.K. attack shines spotlight on deadly nerve agent developed by Soviet scientists," 19 Mar. 2018 The alkyl chloride and organophosphate precursors are toxic, but not nearly to the degree of VX, which was developed in the 1950s for chemical warfare and is the most potent of all nerve agents. Ben Otto, WSJ, "Lethal Weapon: How Kim Jong Nam’s Alleged Killers May Have Unleashed VX," 6 Oct. 2017 Dragna recommends finding personal care products that contain surfactants from the alkyl polyglycosides instead, the most common of which is decyl glucoside, because the head group is a sugar instead of a sulfate. Ajc Homepage, ajc, "Watch the label: Here's how sulfates can affect your hair," 28 Aug. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'alkyl.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of alkyl


1882, in the meaning defined above


1889, in the meaning defined above

History and Etymology for alkyl


probably from German, from Alkohol alcohol

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Time Traveler for alkyl

Time Traveler

The first known use of alkyl was in 1882

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Statistics for alkyl

Cite this Entry

“Alkyl.” Dictionary, Merriam-Webster, Accessed 30 May. 2020.

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al·​kyl | \ ˈal-kəl How to pronounce alkyl (audio) \

Medical Definition of alkyl

 (Entry 1 of 2)

: of, relating to, or being an alkyl alkyl mercurials attack the brain cells— L. J. Goldwater



Medical Definition of alkyl (Entry 2 of 2)

1 : a monovalent aliphatic radical CnH2n+1 (as methyl) broadly : a monovalent aliphatic, aromatic-aliphatic, or alicyclic hydrocarbon radical
2 : a compound of one or more alkyl groups with a metal

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